[Mesa-dev] [PATCH 2/6] st/mesa: overhaul vertex setup for clearing, glDrawPixels, glBitmap

[Ilia Mirkin]

On Fri, Feb 12, 2016 at 10:43 AM, Brian Paul <brianp at vmware.com> wrote:
> diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
> index 9016846..cb2c390 100644
> --- a/src/mesa/state_tracker/st_context.c
> +++ b/src/mesa/state_tracker/st_context.c
> @@ -241,16 +241,23 @@ st_create_context_priv( struct gl_context *ctx, struct pipe_context *pipe,
>     else
>        st->internal_target = PIPE_TEXTURE_RECT;
>
> -   /* Vertex element objects used for drawing rectangles for glBitmap,
> -    * glDrawPixels, glClear, etc.
> +   /* Setup vertex element info for 'struct st_util_vertex'.
>      */
> -   for (i = 0; i < ARRAY_SIZE(st->velems_util_draw); i++) {
> -      memset(&st->velems_util_draw[i], 0, sizeof(struct pipe_vertex_element));
> -      st->velems_util_draw[i].src_offset = i * 4 * sizeof(float);
> -      st->velems_util_draw[i].instance_divisor = 0;
> -      st->velems_util_draw[i].vertex_buffer_index =
> -            cso_get_aux_vertex_buffer_slot(st->cso_context);
> -      st->velems_util_draw[i].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
> +   {
> +      const unsigned slot = cso_get_aux_vertex_buffer_slot(st->cso_context);

Can the aux vertex buffer slot change over time? If so, you need some
logic to update the vertex_buffer_index for these. From what I can
tell it's always 0, not sure what the intention behind it is... seems
like it'll be a very annoying problem to debug down the line should it
ever change. Thoughts?

> +
> +      STATIC_ASSERT(sizeof(struct st_util_vertex) == 9 * sizeof(float));
> +
> +      memset(&st->util_velems, 0, sizeof(st->util_velems));
> +      st->util_velems[0].src_offset = 0;
> +      st->util_velems[0].vertex_buffer_index = slot;
> +      st->util_velems[0].src_format = PIPE_FORMAT_R32G32B32_FLOAT;
> +      st->util_velems[1].src_offset = 3 * sizeof(float);
> +      st->util_velems[1].vertex_buffer_index = slot;
> +      st->util_velems[1].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
> +      st->util_velems[2].src_offset = 7 * sizeof(float);
> +      st->util_velems[2].vertex_buffer_index = slot;
> +      st->util_velems[2].src_format = PIPE_FORMAT_R32G32_FLOAT;
>     }
>
>     /* we want all vertex data to be placed in buffer objects */